28128355861 has 8 divisors (see below), whose sum is σ = 28299608064. Its totient is φ = 27957278160.

The previous prime is 28128355789. The next prime is 28128355867. The reversal of 28128355861 is 16855382182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28128355861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28128355867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 287340 + ... + 372586.

It is an arithmetic number, because the mean of its divisors is an integer number (3537451008).

Almost surely, 2^28128355861 is an apocalyptic number.

It is an amenable number.

28128355861 is a deficient number, since it is larger than the sum of its proper divisors (171252203).

28128355861 is a wasteful number, since it uses less digits than its factorization.

28128355861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87251.

The product of its digits is 921600, while the sum is 49.

The spelling of 28128355861 in words is "twenty-eight billion, one hundred twenty-eight million, three hundred fifty-five thousand, eight hundred sixty-one".